JP2020004581A - Surge protection element and method of manufacturing the same - Google Patents

Abstract

To provide a surge protection element, having a functional film such as a trigger film between electrodes, capable of producing a very narrow gap at a low cost and a method of manufacturing the same.SOLUTION: The surge protection element includes: an insulating tube 2; a pair of sealing electrodes 3 for closing both end openings of the insulating tube and sealing a discharge control gas therein; and an interval adjusting member 4 for defining an interval between the pair of sealing electrodes, by being sandwiched between opposing surfaces of the pair of sealing electrodes in a state where a part is left open as a discharge space S between the pair of sealing electrodes. The interval adjusting member includes: an insulating portion 6a for electrically insulating the pair of the sealing electrodes from each other; and a functional portion 6b containing a conductive material in a state where a part thereof is exposed to the discharge space.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a surge protection element used to protect various devices from a surge generated by a lightning strike or the like and prevent an accident from occurring, and a method of manufacturing the same.

  Telecommunications equipment such as telephones, facsimiles, modems, etc., connected to communication lines, power lines, antennas or image display drive circuits such as CRTs, liquid crystal televisions and plasma televisions, abnormal voltages such as lightning surges and static electricity A surge protection element is connected to a part which is easily affected by electric shock due to (surge voltage) in order to prevent an electronic device or a printed circuit board on which the device is mounted from being damaged by heat or fire due to abnormal voltage.

  2. Description of the Related Art Conventionally, for example, Patent Literature 1 describes a microgap type surge protection element in which a member covered with conductive coating is sandwiched between metal members facing each other in a glass tube. This micro-gap type surge protection element has a structure in which a slit (gap) of several μm to several tens μm is provided at the center of a conductively coated member, and no current flows between opposing metal members below a specified voltage. . When the voltage exceeds the set voltage, an arc discharge occurs between the slits, and a current flows between the opposed metal members.

This surge protection element is a device that utilizes the shape changeability of a glass tube due to softening of glass and the characteristics of joining with a metal, and has excellent mass productivity, and is therefore used in a wide range of fields.
In addition, Patent Document 2 discloses a surge protection device including a cylindrical body formed of ceramics or glass, and a pair of electrodes facing each other with a predetermined space therebetween by interposing an electrically insulating ring-shaped spacer. An element is described. A surge protection element in which the opposing electrode is sealed with a ceramic cylindrical body such as alumina as in such a surge protection element is called an arrester.

Further, in Patent Document 3, an insulating tube, a pair of sealing electrodes for closing the opening at both ends of the insulating tube to seal the discharge control gas therein, and a pair of sealing electrodes provided inside the pair of sealing electrodes A surge absorber includes a pair of protruding electrode members protruding inward and a trigger film formed of a conductive material on an inner peripheral surface of an insulating tube.
In this surge absorber, a trigger film made of a conductive material such as carbon is formed on the inner peripheral surface of the insulating tube, and a trigger discharge is generated through the trigger film to obtain stable discharge characteristics. I have.

JP-B-63-57918 JP-A-63-318085 JP 2017-54586 A

The following problems remain in the above-described conventional technology.
In other words, the glass-coated microgap surge protection element has good bonding properties between glass and metal members, and has excellent reliability such as gas sealing properties and air and moisture blocking properties. However, since the slit width constituting the microgap is small and the thickness of the conductive coating forming the periphery of the microgap is as thin as several tens of μm, the surge withstand capability is limited to about 1500A. In addition, a film forming step of a conductive coating and a laser processing step for forming a micro gap are required, so that the steps become complicated, the production takes time, and the cost is increased.
On the other hand, the arrester-type surge protection element has a withstand capacity of 2000A for a product with a diameter of 5 mm and a resistance of 5000 A for a product with a diameter of 8 mm, and has a surge withstand characteristic higher than that of a glass-coated micro gap type surge protector. I have. Such an arrester-type surge protection element is used for infrastructure equipment such as large home appliances, solar power generation, and water and sewage that require high reliability. The arrester-type surge protection element requires an expensive bonding agent (silver-based brazing material) and an alumina cylindrical member that is more expensive than a glass cylindrical member in joining metal and ceramics. In addition, very high technology is required for joining ceramics and metal parts, and an auxiliary electrode material (such as graphite) is provided inside the electrode, and a dielectric material is applied to the surface of the counter electrode for the purpose of protecting the electrode and promoting discharge. And the production process is complicated. Therefore, the manufacturing cost tends to be significantly higher than that of the glass-coated micro gap type surge protection element. In particular, in the case of using for countermeasures against static electricity, it is necessary to separate electrodes facing each other at a very small interval such as the above-mentioned micro gap, and it has been difficult to set the gap with high accuracy.
In addition, a surge protection element having a trigger film formed on the inner peripheral surface of the insulating tube requires a step of forming a trigger film on the inner peripheral surface of the insulating tube, and a predetermined position on the inner peripheral surface of the insulating tube. However, there is an inconvenience that it is difficult to form a trigger film. As described above, providing a functional film formed of a conductive material such as a trigger film on the inner peripheral surface of the insulating tube has caused an increase in manufacturing steps and manufacturing costs.

  The present invention has been made in view of the above-mentioned problems, and has a functional film such as a trigger film between electrodes and can manufacture a very narrow gap at a low cost, and a manufacturing method thereof. The aim is to provide a method.

  The present invention has the following features to attain the object mentioned above. That is, a surge protection element according to a first aspect of the present invention includes an insulating tube, a pair of sealing electrodes for closing both ends of the insulating tube to seal a discharge control gas therein, and a pair of the sealing electrodes. A gap adjusting unit that is sandwiched between opposing surfaces of the pair of sealing electrodes and defines a gap between the pair of sealing electrodes in a state where a part of the sealing electrodes is left as a discharge space, and the gap adjusting unit However, it is characterized in that it comprises an insulating portion that electrically insulates between the pair of sealing electrodes, and a functional portion containing a conductive material while being partially exposed to the discharge space. .

In this surge protection element, the gap adjusting section includes an insulating section that electrically insulates between the pair of sealing electrodes, and a functional section that contains a conductive material while being partially exposed to the discharge space. Therefore, even if the gap is narrow, a functional portion can be provided between the sealing electrodes more easily than forming the functional portion on the inner peripheral surface of the insulating tube.
Also, by changing the region (thickness and area) of the functional part, the amount of exposure of the functional part to the discharge space can be easily set, and the discharge characteristics can be adjusted by the conductive functional part. Will be possible.
Further, by using the arrester-type counter electrode, high durability and high reliability can be obtained while being small.

A surge protection element according to a second aspect is the surge protection element according to the first aspect, wherein the insulating tube has a cylindrical shape, and the interval adjusting portion has an annular shape in which an outer peripheral edge is in contact with an inner peripheral surface of the insulating tube. It is characterized by being formed in.
That is, in this surge protection element, since the interval adjusting portion is formed in an annular shape in which the outer peripheral edge is in contact with the inner peripheral surface of the insulating tube, the functional portion is exposed inside the interval adjusting portion and the discharge space is formed. Can be secured.

A surge protection element according to a third aspect is the surge protection element according to the first aspect, wherein the insulating tube has a cylindrical shape, and the gap adjusting portion is disposed at a central portion of the facing surface, and is formed in a circular shape. It is characterized by having.
That is, in this surge protection element, the interval adjusting portion is disposed at the center of the facing surface and is formed in a circular shape, so that the functional portion is exposed outside the interval adjusting portion and a discharge space is secured. be able to. Further, the gap adjusting portion disposed at the center portion of the facing surface serves as a barrier, and it is possible to suppress the metal component generated by the arc discharge from scattering to the discharge space on the opposite side in the radial direction of the insulating tube.

A surge protection element according to a fourth aspect is the surge protection element according to any of the first to third aspects, wherein the functional portion contains an ion source material.
That is, in this surge protection element, since the functional portion contains the ion source material, it can be a functional portion having a discharge assisting function as a trigger for arc discharge.

A surge protection element according to a fifth aspect of the present invention is the surge protection element according to any one of the first to third aspects, wherein the functional part is laminated between the insulating parts, and the functional part is formed of metal. It is characterized by having.
That is, in this surge protection element, since the functional portion is formed of a metal, the scattered metal component easily adheres to the functional portion of the metal, and it is possible to suppress the metal component from adhering to the insulating portion.

A surge protection element according to a sixth aspect is characterized in that, in any one of the first to third aspects, the functional part is a functional sheet formed of a conductive material.
That is, in this surge protection element, since the functional portion is a functional sheet containing a conductive material, even a material that is difficult to form a film can be separately formed into a sheet and installed as a functional sheet.

A surge protection element according to a seventh invention is the surge protection device according to any one of the first to sixth inventions, wherein the insulating part is also the functional part containing conductive particles in an insulating material. Features.
That is, in this surge protection element, the insulating part is also a functional part containing conductive particles in the insulating material, so the insulating part is formed by the conductive particles such as the ion source material in the insulating part. The part itself becomes a functional part having a discharge auxiliary function or the like as a trigger for arc discharge.

The surge protection element according to an eighth aspect is characterized in that, in any one of the first to seventh aspects, the insulating tube is a glass tube.
That is, in this surge protection element, since the insulating tube is a glass tube, it can be manufactured at a lower cost than ceramics such as alumina, and at the same time, has excellent reliability due to high gas sealing property and moisture blocking property. Can be

A method for manufacturing a surge protection element according to a ninth invention is a method for manufacturing the surge protection element according to any one of the first to eighth inventions, wherein at least one of the pair of sealing electrodes has a facing surface. An interval adjusting portion forming step of partially forming an interval adjusting portion for defining an interval between the pair of sealing electrodes, and closing both end openings of the insulating tube with the pair of sealing electrodes to discharge inside. A sealing step of sealing the control gas and sandwiching the gap adjusting portion between the opposing surfaces of the pair of sealing electrodes in a state where a part of the sealing gas is left as a discharge space between the pair of sealing electrodes. The gap adjusting section forming step includes a thin film layer forming step of forming a single layer or a plurality of thin film layers on at least one opposing surface of the pair of sealing electrodes, and the thin film layer forming step includes: As at least one of the layers, the insulating portion is made of an insulating material. Forming an insulating portion, and forming a functional portion including at least one of the thin film layers in a state of being partially exposed to the discharge space and containing a conductive material. It is characterized by having.
That is, in the method for manufacturing a surge protection element, the gap adjusting portion forming step includes a thin film layer forming step of forming a single layer or a plurality of thin film layers on at least one opposing surface of the pair of sealing electrodes, A layer forming step of forming an insulating portion with an insulating material as at least one of the thin film layers; and a state in which at least one of the thin film layers is partially exposed to the discharge space. And a functional part forming step of forming a functional part containing a conductive material, so that a thin film layer or a functional part can be easily formed in a thin and various shape by patterning, and a narrow gap is provided. Can be.

The method for manufacturing a surge protection element according to a tenth aspect is the ninth aspect, wherein in the thin film layer forming step, a paste containing a material to be the thin film layer is partially applied to the facing surface. The method is characterized in that a layer is formed.
That is, in the method of manufacturing the surge protection element, in the thin film layer forming step, the thin film layer is formed by partially applying the paste containing the material to be the thin film layer to the opposing surface. A thin film layer can be formed easily and easily.

A method for manufacturing a surge protection element according to an eleventh aspect of the present invention is the ninth or tenth aspect, wherein the insulating portion forming step is an insulating material containing conductive particles and also the functional portion. Forming a portion.
That is, in the method of manufacturing the surge protection element, the insulating portion forming step forms the insulating portion that is also the functional portion with the insulating material containing the conductive particles. And an insulating portion functioning as a functional portion can be formed in one step.

According to the present invention, the following effects can be obtained.
That is, according to the surge protection element and the method of manufacturing the same according to the present invention, the gap adjusting portion is electrically connected to the insulating portion electrically insulating the pair of sealing electrodes from each other, and is electrically conductive in a state where the sealing portion is partially exposed to the discharge space. Since the functional portion containing the functional material is provided, the functional portion can be provided between the sealing electrodes more easily than when the functional portion is formed on the inner peripheral surface of the insulating tube even if the gap is narrow.
In addition, it can be manufactured at low cost, and can achieve high withstand capacity and high reliability despite its small size.
Therefore, the surge protection device according to the present invention is suitable for a power supply circuit unit and a communication circuit unit of an electric device that requires a small, inexpensive, and highly reliable product. In particular, the surge protection element of the present invention is suitable for a wide range of applications including measures against static electricity for mounting on a substrate.

FIG. 2 is an axial sectional view showing the surge protection element in the first embodiment of the surge protection element and the method of manufacturing the same according to the present invention. FIG. 2 is an exploded perspective view showing the surge protection element in the first embodiment. FIG. 6 is an axial sectional view showing a surge protection element in a second embodiment of the surge protection element and the method of manufacturing the same according to the present invention. It is an exploded perspective view showing a surge protection element in a 2nd embodiment. FIG. 9 is an axial sectional view showing a surge protection element in a third embodiment of the surge protection element and the method of manufacturing the same according to the present invention.

  Hereinafter, a first embodiment of a surge protection element and a method of manufacturing the same according to the present invention will be described with reference to FIGS. In each drawing used in the following description, the scale is appropriately changed in order to make each member a recognizable or easily recognizable size.

As shown in FIGS. 1 and 2, the surge protection element 1 of the present embodiment includes an insulating tube 2 and a pair of sealing members for closing the openings at both ends of the insulating tube 2 to seal the discharge control gas therein. An interval defining the interval between the pair of sealing electrodes 3 sandwiched between the opposing surfaces of the pair of sealing electrodes 3 in a state where a part thereof is provided as a discharge space S between the stop electrode 3 and the pair of sealing electrodes 3. And an adjusting unit 4.
The gap adjusting section 4 includes an insulating section 6a for electrically insulating the pair of sealing electrodes 3 from each other, and a functional section 6b containing a conductive material while being partially exposed to the discharge space S. ing.

  The interval adjusting section 4 of the present embodiment includes a plurality of thin film layers provided on the facing surface, and at least one of the thin film layers is an insulating section 6a formed of an insulating material. At least one layer is a functional part 6b containing a conductive material in a state where a part thereof is exposed to the discharge space.

The insulating tube 2 has a cylindrical shape and is formed of a glass tube of lead glass or the like. Note that the insulating tube 2 is preferably formed of a glass tube which is inexpensive and has excellent sealing properties, but may be formed of a crystalline ceramic material such as alumina.
The discharge control gas sealed in the insulating tube 2 is an inert gas or the like, for example, He, Ar, Ne, Xe, Kr, SF ₆ , CO ₂ , C ₃ F ₈ , C ₂ F ₆ , CF ₄ , H ₂ , atmosphere, etc., and a mixed gas thereof are employed.

The sealing electrode 3 is formed of, for example, a dumet wire, a 42 alloy (Fe: 58 wt%, Ni: 42 wt%), Cu, or the like in a columnar shape.
In the present embodiment, the pair of sealing electrodes 3 enter the inside of the insulating tube 2 to close the openings at both ends.
The base end of the lead wire 5 projecting outward is embedded in each sealing electrode 3.

The gap adjusting section 4 of the present embodiment includes three layers of an insulating section 6a formed directly on the surface facing the sealing electrode 3 and a functional section 6b stacked between the pair of insulating sections 6a. It is composed of
The space adjusting section 4 is formed in an annular shape in which the outer peripheral edge is in contact with the inner peripheral surface of the insulating tube 2.
Therefore, a substantially disk-shaped discharge space S is formed inside the space adjustment unit 4.

  In this embodiment, the insulating portion 6a and the functional portion 6b have the same shape (an annular thin film layer having the same outer diameter and the same inner diameter). And the discharge space S can be ensured, and as long as a part of the functional portion 6b is exposed to the discharge space S, the shapes may be different from each other.

The thickness and the number of the insulating portions 6a and the functional portions 6b to be laminated are set so that the interval adjusting portion 4 has a thickness of, for example, 200 to 800 μm. That is, the thickness of the gap adjusting section 4 becomes the distance between the sealing electrodes.
In addition, it is preferable that the installation area of the space adjustment unit 4 with respect to the facing surface of the sealing electrode 3 be set to 50% or less of the area of the facing surface. That is, the reason why the installation area of the gap adjusting section 4 is set to be within 50% is that if it exceeds 50%, a sufficient discharge space S cannot be secured.

The functional part 6b is a functional sheet formed of a conductive material.
Particularly, in the present embodiment, the functional portion 6b is formed of an ion source material.
For example, the functional part 6b is a discharge auxiliary part formed of a material that is an ion source material and has a higher electron emission ability than the sealing electrode 3, a carbon material, or the like. The functional part 6b is, for example, an annular graphite sheet.

  In the method of manufacturing the surge protection element 1 according to the present embodiment, an interval in which at least one of the pair of sealing electrodes 3 is opposed to the gap adjusting portion 4 for defining the interval between the pair of sealing electrodes 3 is partially formed. An adjusting portion forming step, and a pair of sealing electrodes 3 close both ends of the insulating tube 2 to seal a discharge control gas therein, and a part of the discharge space is formed between the pair of sealing electrodes 3. And a sealing step of sandwiching the gap adjusting portion 4 between the opposing surfaces of the pair of sealing electrodes 3 in a state where S is left.

The interval adjusting section forming step includes a thin film layer forming step of forming a plurality of thin film layers on at least one opposing surface of the pair of sealing electrodes 3.
The thin film layer forming step includes an insulating portion forming step of forming an insulating portion 6a of an insulating material as at least one of the thin film layers, and a part of the thin film layer in the discharge space S as at least one of the thin film layers. Forming a functional portion 6b that is exposed and that contains a conductive material.

In the functional part laminating step of the present embodiment, the functional part 6b formed of a conductive material is sandwiched between the insulating parts 6a formed on the opposing surfaces of the pair of sealing electrodes 3.
In the thin film layer forming step, the insulating portion 6a is formed by partially applying a paste containing an insulating material to be the insulating portion 6a to the opposing surface.
As the paste, for example, a paste containing ceramics, glass, resin powder, or the like as a main paste material is employed.

In the present embodiment, the paste is applied in an annular shape to both opposing surfaces of the pair of sealing electrodes 3 and patterned, and the insulating portion 6a is formed directly on the opposing surfaces.
As shown in FIG. 2, when a pair of sealing electrodes 3 having the insulating portions 6a formed thereon are inserted into the insulating tube 2 in a facing state, a function as a functional sheet is provided between the pair of sealing electrodes 3. The insulating portion 6b is disposed, and is opposed to each other while being sandwiched between the pair of insulating portions 6a. In this state, the insulating tube 2 and the sealing electrode 3 are joined by heat treatment, whereby the surge protection element 1 having the gap adjusting section 4 is manufactured.

  In this surge protection element 1, when an overvoltage or an overcurrent enters, an initial discharge is first performed between the functional portion 6b serving as a discharge auxiliary portion and the sealing electrode 3, and further discharge is triggered by the initial discharge. As it progresses, arc discharge is performed from one sealing electrode 3 to the other sealing electrode 3.

  As described above, in the surge protection element 1 according to the present embodiment, the interval adjusting section 4 is configured such that the gap adjusting section 4 electrically connects the pair of sealing electrodes 3 to the insulating section 6 a and electrically connects the insulating section 6 a to the discharge space S in a partially exposed state. And the functional portion 6b containing a functional material, so that the functional portion 6b can be provided between the sealing electrodes 3 more easily than on the inner peripheral surface of the insulating tube 2 even if the gap is narrow. Can be.

Further, by changing the thickness and area of the functional portion 6b, the amount of exposure of the functional portion 6b to the discharge space S can be easily set, and the discharge characteristics can be adjusted by the conductive functional portion 6b. Becomes possible.
Further, since the functional portion 6b is formed of an ion source material, the functional portion 6b having a discharge assisting function as a trigger for arc discharge can be provided.
In particular, since the functional portion 6b is a functional sheet formed of a conductive material, even a material that is difficult to form a film can be separately formed into a sheet and installed as a functional sheet.

Further, by using the arrester-type counter electrode, high durability and high reliability can be obtained while being small.
In particular, since the insulating tube 2 is a glass tube, the insulating tube 2 can be manufactured at a lower cost than ceramics such as alumina, and excellent reliability can be obtained due to a high gas sealing property and a barrier property against moisture and the like.
Further, since the gap adjusting section 4 is formed in an annular shape in which the outer peripheral edge is in contact with the inner circumferential surface of the insulating tube 2, the functional section 6 b is exposed inside the gap adjusting section 4 and the discharge space S is formed. Can be secured.

Further, in the method for manufacturing the surge protection element 1 according to the present embodiment, the step of forming the gap adjusting portion includes a step of forming a plurality of thin film layers on at least one of the opposing surfaces of the pair of sealing electrodes 3. ing.
The thin film layer forming step includes an insulating portion forming step of forming an insulating portion 6a of an insulating material as at least one of the thin film layers, and a part of the thin film layer in the discharge space S as at least one of the thin film layers. A functional portion forming step of forming a functional portion 6b that is exposed and contains a conductive material, so that the insulating portion 6a can be easily formed in a variety of thin shapes by patterning, A narrow gap can be provided in a state where the functional part 6a is stacked with the functional part 6b sandwiched therebetween.
In particular, in the insulating portion forming step, the insulating portion 6a is formed by partially applying a paste containing an insulating material to be the insulating portion 6a to the opposing surface, so that patterning by paste application is simple and easy. The insulating portion 6a can be formed as a film.

  Next, second and third embodiments of the surge protection element according to the present invention will be described below with reference to FIGS. In the following description of each embodiment, the same components described in the above embodiment will be denoted by the same reference numerals, and description thereof will be omitted.

The difference between the second embodiment and the first embodiment is that, in the first embodiment, the interval adjusting unit 4 is configured by overlapping the annular insulating portion 6a and the functional portion 6b. As shown in FIGS. 3 and 4, the surge protection element 21 according to the second embodiment is configured such that the circular insulating section 26a and the functional section 26b are overlapped to form the interval adjusting section 24.
That is, in the second embodiment, the interval adjusting unit 24 is disposed at the center of the opposing surface of the sealing electrode 3, and the insulating unit 26a and the functional unit 26b are formed in a circular shape having a common axis. I have.

By arranging the space adjusting portion 24 in the center portion of the facing surface in this way, a substantially annular discharge space S is formed outside the space adjusting portion 24.
The gap adjusting section 24 of the present embodiment is formed of three layers in which an insulating section 26a and a functional section 26b formed directly on the surface facing the sealing electrode 3 are overlapped in the axial direction.

Further, in the first embodiment, the functional portion 6b is formed of an ion source material, whereas in the second embodiment, the functional portion 26b is formed of a metal.
The functional portion 26b of the second embodiment is formed in a sheet shape from, for example, the same metal as 42 alloy or Cu as the sealing electrode 3.

In the second embodiment, the paste is applied in a circular shape to both of the opposing surfaces of the pair of sealing electrodes 3 and patterned, and the insulating portion 26a is formed directly on the opposing surfaces.
As shown in FIG. 4, when the pair of sealing electrodes 3 on which the insulating portions 26a are formed are inserted into the insulating tube 2 in a facing state, a function as a functional sheet is provided between the pair of sealing electrodes 3. The insulating portion 26b is disposed, and is opposed to each other while being sandwiched between the insulating portions 26a. In this state, the insulating tube 2 and the sealing electrode 3 are joined by heat treatment, whereby the surge protection element 21 having the gap adjusting portion 24 is manufactured.

As described above, in the surge protection element 21 of the second embodiment, since the functional portion 26b is formed of a metal, the scattered metal component easily adheres to the metal functional portion 26b, and the insulating portion 26a Adhesion can be suppressed.
In addition, the gap adjusting section 24 is disposed at the center of the facing surface, and the insulating section 26a and the functional section 26b are formed in a circular shape having a common axis. The functional space 26b is exposed, and the discharge space S can be secured. Further, the gap adjusting portion 24 disposed in the center portion of the facing surface serves as a barrier, so that it is possible to suppress the metal component generated by the arc discharge from scattering to the discharge space S on the opposite side in the radial direction of the insulating tube 2.

  The difference between the third embodiment and the first embodiment is that, in the second embodiment, the interval adjusting unit 24 is configured such that the insulating unit 26a and the functional unit 26b are formed directly on the opposing surface of the sealing electrode 3. Are formed in three layers superposed in the axial direction. On the other hand, in the surge protection element 31 of the third embodiment, as shown in FIG. The point is that it is constituted by the insulating portion 36a which is a single thin film layer provided.

Further, the insulating portion 36a of the third embodiment is different from the first embodiment in that it is also a functional portion containing conductive particles C in an insulating material.
That is, the insulating portion 36a contains the conductive particles C such as an ion source material in a dispersed state while maintaining the insulating property as a whole.
For example, the insulating portion 36a contains carbon particles as an ion source material as conductive particles C in the insulating material, and some of the conductive particles C are exposed on the surface of the peripheral portion.

In the thin film layer forming step (insulating portion forming step) of the third embodiment, a paste containing an insulating material containing conductive particles C to be the insulating portion 36a is partially applied to one of the opposing surfaces of the pair of sealing electrodes 3. To form an insulating portion 36a.
As the paste, for example, a paste containing ceramics, glass, resin powder, or the like as a main paste material is employed, and carbon particles are contained as conductive particles C.

As described above, in the surge protection element 31 of the third embodiment, since the insulating portion 36a contains the conductive particles C in the insulating material, the conductive particles such as the ion source material in the insulating portion 36a are included. With C, the insulating portion 36a itself can have a discharge assist function or the like as a trigger for arc discharge.
In addition, since the insulating portion forming step forms the insulating portion 36a which is also a functional portion with an insulating material containing the conductive particles C, there is no need to separately perform the functional portion forming step, and the process is performed in one step. The insulating portion 36a functioning as a functional portion can be formed.

  Note that the technical scope of the present invention is not limited to the above embodiments, and various changes can be made without departing from the spirit of the present invention.

For example, it is preferable that the insulating portion is formed by the paste coating method as in the above embodiments, but another film forming method such as sputtering may be adopted.
In the first and second embodiments, the functional portion of the functional sheet is used. However, the functional portion of the thin film layer may be formed by a paste coating method or the like.
Further, in the first and second embodiments, the gap adjusting section is constituted by three layers of two insulating sections and one functional section, but two or more functional sections sandwiched between the insulating sections are provided. The distance adjusting unit may be provided with four or more layers.
Further, in the third embodiment, the single-layer functional portion is formed by the paste coating method, but an insulating sheet containing conductive particles may be provided between the facing surfaces.

  1, 21, 31 ... surge protection element, 2 ... insulating tube, 3 ... sealing electrode, 4, 24, 34 ... interval adjusting section, 6a, 26a, 36a ... insulating section, 6b, 26b ... functional section, S: discharge space

Claims (11)

An insulating tube;
A pair of sealing electrodes for closing the opening at both ends of the insulating tube and sealing the discharge control gas inside,
An interval adjuster that is interposed between opposing surfaces of the pair of sealing electrodes in a state in which a part is provided as a discharge space between the pair of sealing electrodes, and defines an interval between the pair of sealing electrodes,
The gap adjusting section is an insulating section that electrically insulates between the pair of sealing electrodes,
And a functional part containing a conductive material in a state where a part thereof is exposed to the discharge space. The surge protection device according to claim 1,
The insulating tube is cylindrical,
The surge protector according to claim 1, wherein the gap adjusting section is formed in an annular shape with an outer peripheral edge in contact with an inner peripheral surface of the insulating tube. The surge protection device according to claim 1,
The insulating tube is cylindrical,
The surge protection element is characterized in that the gap adjusting section is arranged at a central portion of the facing surface and is formed in a circular shape. The surge protection device according to any one of claims 1 to 3,
A surge protection element, wherein the functional part contains an ion source material. The surge protection device according to any one of claims 1 to 3,
The surge protector according to claim 1, wherein the functional portion is laminated and sandwiched between the insulating portions, and is formed of metal. The surge protection device according to any one of claims 1 to 3,
The surge protector, wherein the functional part is a functional sheet containing a conductive material. The surge protection device according to any one of claims 1 to 6,
A surge protection element, wherein the insulating portion is also the functional portion containing conductive particles in an insulating material. The surge protection device according to any one of claims 1 to 7,
2. The surge protection device according to claim 1, wherein the insulating tube is a glass tube. A method for manufacturing a surge protection device according to any one of claims 1 to 8,
An interval adjusting portion forming step of partially forming an interval adjusting portion for defining an interval between the pair of sealing electrodes on at least one facing surface of the pair of sealing electrodes,
A pair of the sealing electrodes close the openings at both ends of the insulating tube to seal the discharge control gas therein, and a pair of the sealing electrodes in a state where a part thereof is opened as a discharge space between the sealing electrodes. A sealing step of sandwiching the gap adjusting portion by the opposing surface of the sealing electrode,
The interval adjusting portion forming step includes a thin film layer forming step of forming a single layer or a plurality of thin film layers on at least one facing surface of the pair of sealing electrodes,
The thin film layer forming step, as at least one of the thin film layers, an insulating portion forming step of forming an insulating portion with an insulating material;
A functional part forming step of forming a functional part containing a conductive material in a state where a part thereof is exposed to the discharge space, as at least one of the thin film layers. Manufacturing method of surge protection element. The method for manufacturing a surge protection element according to claim 9,
The method for manufacturing a surge protection element, wherein in the thin film layer forming step, a paste containing a material to be the thin film layer is partially applied to the facing surface to form the thin film layer. The method for manufacturing a surge protection element according to claim 9 or 10,
The method for manufacturing a surge protection element, wherein the insulating portion forming step includes forming the insulating portion, which is also the functional portion, with an insulating material containing conductive particles.

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